nimble/ll: Remove redundant check
nimble/ll: Remove redundant check

There is no need to check for BLE_LL_ADV_SM_FLAG_ADV_TERMINATE_EVT in
ble_ll_adv_sec_done() since this flag is always set for extended
advertising and secondary channels are only active in case of extended
advertising.

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble